MAINT: include benchmarks and dev files in sdist.
MAINT: include benchmarks and dev files in sdist.

Closes gh-6498.

[ci skip] [skip ci]

matthew-brett/scipy,anntzer/scipy,andyfaff/scipy,rgommers/scipy,pizzathief/scipy,e-q/scipy,tylerjereddy/scipy,lhilt/scipy,arokem/scipy,gfyoung/scipy,lhilt/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,nmayorov/scipy,grlee77/scipy,endolith/scipy,gfyoung/scipy,nmayorov/scipy,vigna/scipy,WarrenWeckesser/scipy,zerothi/scipy,WarrenWeckesser/scipy,zerothi/scipy,Eric89GXL/scipy,e-q/scipy,aarchiba/scipy,matthew-brett/scipy,aeklant/scipy,aarchiba/scipy,zerothi/scipy,mdhaber/scipy,vigna/scipy,rgommers/scipy,rgommers/scipy,vigna/scipy,pizzathief/scipy,andyfaff/scipy,WarrenWeckesser/scipy,gertingold/scipy,anntzer/scipy,perimosocordiae/scipy,Eric89GXL/scipy,aeklant/scipy,scipy/scipy,jor-/scipy,ilayn/scipy,jamestwebber/scipy,person142/scipy,vigna/scipy,person142/scipy,mdhaber/scipy,zerothi/scipy,endolith/scipy,arokem/scipy,arokem/scipy,Stefan-Endres/scipy,mdhaber/scipy,zerothi/scipy,jamestwebber/scipy,pizzathief/scipy,jamestwebber/scipy,lhilt/scipy,rgommers/scipy,tylerjereddy/scipy,matthew-brett/scipy,aeklant/scipy,aarchiba/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,pizzathief/scipy,Eric89GXL/scipy,e-q/scipy,rgommers/scipy,person142/scipy,nmayorov/scipy,WarrenWeckesser/scipy,mdhaber/scipy,scipy/scipy,scipy/scipy,andyfaff/scipy,matthew-brett/scipy,mdhaber/scipy,zerothi/scipy,Stefan-Endres/scipy,ilayn/scipy,perimosocordiae/scipy,endolith/scipy,nmayorov/scipy,mdhaber/scipy,andyfaff/scipy,anntzer/scipy,ilayn/scipy,grlee77/scipy,gfyoung/scipy,scipy/scipy,person142/scipy,grlee77/scipy,tylerjereddy/scipy,ilayn/scipy,e-q/scipy,aeklant/scipy,gertingold/scipy,gertingold/scipy,grlee77/scipy,gfyoung/scipy,Stefan-Endres/scipy,andyfaff/scipy,anntzer/scipy,person142/scipy,aeklant/scipy,ilayn/scipy,gfyoung/scipy,arokem/scipy,endolith/scipy,aarchiba/scipy,Eric89GXL/scipy,perimosocordiae/scipy,scipy/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,aarchiba/scipy,endolith/scipy,WarrenWeckesser/scipy,tylerjereddy/scipy,jamestwebber/scipy,endolith/scipy,lhilt/scipy,lhilt/scipy,Stefan-Endres/scipy,jor-/scipy,vigna/scipy,ilayn/scipy,tylerjereddy/scipy,jamestwebber/scipy,anntzer/scipy,matthew-brett/scipy,scipy/scipy,gertingold/scipy,jor-/scipy,grlee77/scipy,gertingold/scipy,perimosocordiae/scipy,andyfaff/scipy,Eric89GXL/scipy,jor-/scipy,pizzathief/scipy,arokem/scipy,nmayorov/scipy,jor-/scipy,e-q/scipy,anntzer/scipy